Acetone-resin printing ink



Patented Aug. 11512942 moreparticularly to the use ofY acetone resins" as" to such-:inksiand thatl is their inherent smudging. Because the #mineral o'i1=.does :fnot readily evapo-1y ratevthe: inks-r remain undried :for: relativelyf longl periodSL-oL-fgtimef These' -mineral :roll inks# alsof Other quickedryingltypes; depend more or `'less uponthe use of specialized equipment for quickozonators. Less frequently. anv oxygen bearing; compoundsuch as .a peroxide is. incorporated; inf tlwyehi a;

j "Althoughainks ordinarily are classied as to.- thetype of vehicle they, contain, many, other con`" Stituents SQ into thefmekins 1190i an 1111s. Pig.- men'ts myj be obtaiecffyrom' natural' iksources, dr iay "be manufactured? llista.;y @any modifying to ch erally are incorporated which keep the pigment srecellulose drivveswarlws gasses. slyger'cl and fatty aidsoans- .Paramn waxfmanbeillssd of saiacarletqnlmus, deceased assuma-w Ellis Laboratories YIl,,wcn'pdjilatc' as tan evaporation retardant ,where riasfermldhy'le irji the presen catalyst, that 1S a 'csfalyst .0f

luck-'dryig-inks' offthevolatile 4solventtype are by far the best although some provisionf-lfnay I necessary for removal ofl fumes during thef,m printing process. Recovery systems rnayfybe50p;r4 erate'd ifconjunctin. the use'fofllvolatlie,

` Y?" isili" cards,

se'. such m91);

an `,inexpnsive Waterlsolublegresin bi hyde resin binder'. A furtherbflt 15:50 D;

white or ,other snslosss shades'. f. Thefwt prevasily mnsohzed suf vreferablvv Vrelativ@y lewzbpums www# is.. used warr-svlubleiypes yof resins prepared. accor'l'ling] tolmy invention largeamount of pigl'nent'fth pigment particles ention s to uriiush'zal 'yarthritis@` of pared from very dull to highly glossy inks by varying the pigment to binder ratio.

The method of setting or hardening these inks is by subjection of the printed sheet to a temperature that will volatilize the solvent rapidly..

This ink dried in about 5 seconds at 10 C. and could not be rubbed oi. 'I'he ink had a high gloss and although the nlm produced was hard there was no evidenced! the ink-paper bond breaking ,on bending or crushing the paper.

ll'7.1:ample 'l.-A dull ink was made by using the followingproportion of ingredients:

, Parts Acetone resin (Example 1) 6v Isopropyl alcohol -44 Carbon black The acetone resin and isopropyl alcohol were which the printed sheet is treated should be at l least 50 C. and not higher than about 150 C.

Heating of the printed web or sheets may be ac- A complished by any of the usual methods. A

heated roller, gas ilame, blast of heated air, passage through a furnace or any other method may be Aused .to set the inks.

Other properties that may l readily be varied are length, ow and tack. Because of the` excllent binding qualities o f acetone-formaldehyde resins, smudging'is eliminated even when the amount of binder used is low compared to the amount of pigment. Drying oils are not used in ,conjunction with these binders and consequently theinitial setting is final, that is tosay. neither a prolonged hardening period nor an offset preventative such as a powder or spray isnecessary when binders as disclosed herein are used.

The'following examples will more clearly yde= scribe the application of the acetone-formaldehyde resin binders. I do not wish to be limited to thequantitiesjused or to'the speciiic compounds employed as.' set forth in these examples.

Example 1,-A resin was prepared from 50 parts of acetone, 50 parts of paraiornialdehyde, 5 partsl of disodium phosphate and 1.25 parts of potassium hydroxide. The potassium hydroxide and disodium phosphate were dissolved in the least possible amount o f water and added to the acetone-paraformaldehydemixture. lHeat was applied to start the reaction but thereafter the reaction proceeded without further addition of heat. At the end of 45 minutes a separate layer had -iormed which contained the resin. The two layers were separated and the resinous product washed until free of alkali or vany unreacted acetone. paraformaldehyde or phosphate.

The product was clear and insoluble in acetone or benzene. By using xylol as a solvent a 'syrupy solution was obtained. The product was non-v thixotropic.

Example 2.-The resin prepared as described in Example 1 was dissolved in xylol to give a free flowing liquid. Chrome green pigment was added to the resin solution giving a light-green', freeflowing composition which appeared suitable as an ink.

The ink was printed on various types of paper and these placed in an oven which was heated to 100 C. The ink on the paper quickly (six to ten seconds) became hard and could not be rubbed o. The dried print had a high gloss.

Example 3.--Resln syrup as made'in Example 1 was dissolved in isopropyl alcohol. Carbon black was added to the isopropyl solution and a very satisfactory quick-drying ink was produced. The proportion of ingredients was:

. o Parts Acetone-resin syrup 1.9 Isopropyl alcohoLr 3.1

Carbon black mixed andthen the carbon black ground into this mixture. The ink was long, and on heating printed-sheets for 1.5 seconds in an oven at 100 fC. the ink dried t0 a. hard mm. The dry'ink .v was not sticky. This composition also exhibited non-feathering qualities. The ink was dull and non-smudging.

Example 5,.-A resin was made from the following ingredients:

Parts Formalim 50 Acetonef 150 Potassium carbonate 2.5

The potassium carbonate :was dissolved .in the smallest'possibleamount vot water and added to the acetone-formalin mixture. The mixture was heated under reilux for 2.5 hours. Hydrochloric acid subsequently was added until the mixture wasneutral. The water and excess acetone were eliminated from the mixture by evaporation in f Parts Resin Y 47.5

` Abetonel 32.0 Paramn wax 0.5 CarbonI black 20.0V

Theliquid; ingredients'were lmixed and then the pigment ,wasground'into the vehicle. A medium length ink resulted that gave glossy films on drying for-two seconds at C.

Example 7. -Avresin was made from the followingconstituents:

Parts Acetone f 18 Formalin 135 NaOH solution'(50%) f 15 Parts Resin 27 Water 53 Titanox f 20 The ink'was medium in length and ilowed well. Printed sheets gave glossy films when dried at C. for 4.5 seconds.

IIl i'he preceding disclosures illustrate the varied use of acetone-formaldehyde resins as binders in quick-drying printing inks. The resins applicable for use in my invention may readily be made by reacting the two constituents, acetone Y lyneutral and substantially free of hardening-t and formaldehyde, in the presence oi an alkaline catalyst, that is, a catalyst selectedirom the alkaline salts, oxides or hydroxides of alkali metals or alkaline earth metals. By varying the amount of catalyst and the reaction time a water-solu-V -bley resin can be made which becomes water-insoluble when subjected to heat treatment. When the reaction time is lengthened a resin is obtained which is insoluble in water but soluble in many ofthe common organic solvents.

The proportion of binder in the ink composi-v tion may vary within wide limits. If the ratio of binder to pigment is progressively lowered the ink becomes duller and shorter. Even when this ratio reaches the proportions of 1 to 2, there is no smudging of the printed matter, At a ratio of binder to pigment vof 2.5 to 1 the ink has good covering power and high gloss. The length of the ink is in direct proportion to the amount of binder used. Modifying agents such as pigment extenders, hardeners, e. g.. hexa, waxes and other ingredients, may be added to produce spe-A cial properties. Paramn wax is used in certain inks. to retard the evaporation of highly volatile constituents.

Drying oils are not employed with the acetoneresin binders because of the relatively slow dryf ing characteristics of the drying oils.

Water-soluble resins of the acetone-formaldehyde type are very advantageous because oi their low cost and the fact that no fume removal sysvtem is necessary during printing. The latter is unusual in quick-drying inks of the solvent-'removal type, especially when the iinished print is water-insoluble. The ilow of inks containing these binders can be varied within wide limits. No thlxotropic properties are exhibited by the agents and yielding va nlm which hardens on mo mentary subjection to a mild heatingroperation Y at a temperature not exceeding 100 insoluble resin made by interaction of formaldewater-soluble types of acetone-fonnaldehyde' resins. Because ofthe economic advantage this type of Vresin has over other resins in inks, it may be economically used for newsprinting and handbills. The resultingqprinted matterrwill be less subject to show through because of the absence of any mineral oil in the ink composition. Types suitable for most any typographie process can 1 be made from the acetone-formaldehyde resins.

What I claim is: LA quick-drying printing ink composition comprising a binding agent consisting ofa water-v insoluble resin made by interaction 'of formaldehyde with acetone in the presence of an alkaline catalyst, pigmenting material, and a liquid organic solvent, for the resin, that is readily volatile at temperatures between 50 C. and 100 C., said printing ink composition being substantial- 2.V A quick-drying printing ink composition comprising a binding agentconsisting of a waterinsoluble resin made by interaction of formaldehyde-with acetone in the presence oi! an'allraf-l line catalyst, pigmenting material, a liquid organic solvent, for the resin, that is readily volatile at temperatures between 50 and 150 C. and an evaporation retardant, said printing ink' composition being substantially neutral ad substantially free of hardening agents and yielding a iilm which hardensY on momentary subjection to a mild heating operation at a temperature not ex- Y ceeding C.

V3. A quick-drying printing ink composition, according to claim 1, in which the liquid organic solvent isacetone.

`4.111 quick-drying printing ink composition, A' according to claim 1, in which the liquid organic solvent is isopropyl alcohol. Y

5. A quick-drying printing ,ink composition,

according to claim 1, in which the liquid organic solvent ,is xylene.Y

6. A quick-drying printing ink composition comprising a binding agent consisting of, a watermentary subjection'to a mild heating operation at atemperature not exceeding 100 C. Y 7. A quick-drying printing -ink composition comprising a binding agent consisting of a water-insoluble resin 'made by interaction` of formaldehyde with acetone in theV presence of an a1- kaline catalyst, pigmenting material, and a liq uid organic solvent, for the resin, that is readily volatile at temperatures between 50 C. and 100 C., the proportion of Vsaid binding agent being substantially less thanthe proportion oi?y said pigmenting material, said printing ink composition being substantially free of hardening agents and yielding a dull lm which hardens on mo- Y mentary subjection toa mild heating operation at atemperature not eirceeding 100 C.

CARLE'I'ON ELLIS. 

